On the plains of New Mexico, a band of elite marathoners tests a controversial theory of evolution: that humans can outrun the fastest animals on earth.

Between two and three million years ago, when our australo­pithecine ancestors ventured out of the forests and onto the protein-rich African savanna, they were prey more often than hunter. They gathered plant-based foods, just as their primate brethren did. Then something changed. They began running after game with long, steady strides. Evolutionary biologists like Harvard’s Dan Lieberman think the uniquely human capacity for endurance running is a distant remnant of prehistoric persistence hunting.

We can run all day, the theory goes, because there was once a caloric advantage to it. Our two human legs, packed as they are with long slow-twitch muscle fibers, make us better runners over long distances than most quad­rupeds. And our three million sweat glands give us the ability to cool our bodies with perspiration. An antelope, by contrast, sprints—for up to 15 minutes—while wearing a fur coat and relies on respiration (panting) to release the heat that builds up with exertion. Add to the mix our ability to organize and strategize and, well, you can see how persistence hunting might actually work. (…)

There’s no hard archaeological evidence of persistence hunting, but half a dozen tribes are known to have pursued game this way in the past century: the Aborigines in Australia, the Navajo in the American Southwest, the Seri and Tarahumara Indians in Mexico. Of the tribes thought to practice it, though, only the Bushmen of the Kalahari Desert have been seen chasing antelope in recent decades. In the 1980s, South African mathematician Louis Liebenberg joined a successful Bushman persistence hunt for kudu in 107-degree heat.

{ Outside | Continue reading }

related { Does sexual intercourse hinder subsequent athletic performance? }

science, sport | May 24th, 2011